### DESCRIPTIONThis is a Raspberry Pi hat that allows the GPIO pins to be directly interfaced with a wide range of input (±40 V) and output (0 to 100V) voltages. The input is open at -40 V to 0 V and closed at +2V to +40V. Each GPIO pin is in series with a 1 kΩ resistor to limit pin current to 3.3 mA. The PI hat also has an aperture that allows a 20 mm x 20 mm heatsink to be used to cool the CPU, and has a 5V output to power a fan.Input pins: 11, 13, 15, 16, 18Output pins: 22, 29, 31, 36, 37### TECHNICAL DETAILS / COMPONENTSAssembly manual, KiCAD files, CAD files, Gerber files, and parts list can be found at: https://github.com/Llamero/RPi_IO_Hat_v1
